hello! This is my first time asking a question on the forum.Thank you!　I tried using fexpr~ to create a biquad~ filter, but it didn't work. . I don't know how to make a biquad filter using fexpr~.
Could you tell me if I'm wrong somewhere?
Only the low-pass filter worked, but the high-pass filter etc. did not work well. .
The image is a low pass filter.

@fendoap I think you might need one and two sample delays......... https://www.katjaas.nl/hilbert/hilbert.html
and........ https://forum.pdpatchrepo.info/topic/677/biquad-implementation-one-sample-delay
Is there a reason that you do not want to use [biquad~] which will be easier and more efficient...?
David.

@whale-av Thanks so much! 　
I want to control it with an audio signal, so I tried to make it with fexpr~.
Then I tried a few things and it worked! It seems that the spelling of fexpr~ was wrong!
Thanks a lot!

@fendoap Ahhh....easily done..!
It can be a useful patch then.
David.

@whale-av Thank you so much!